Cephalosporin compounds having a substituted amino group in the .alpha.-position of the 7-acylamino side chain have been described in the literature. In U.S. Pat. Nos. 3,673,183 and 3,708,479, .alpha.-ureido cephalosporanic acids are disclosed. Penicillins and cephalosporins having an .alpha.-(3-imidoylureido)arylacetamido side chain are described in U.S. Pat. Nos. 3,634,405 and 3,646,024, respectively. In U.S. Pat. No. 3,687,949, cephalosporins having an .alpha.-(3-acylureido)arylacetamido side chain are disclosed. This latter patent defines a wide variety of acyl groups attached to the terminal nitrogen of the .alpha.-ureido group of the 7-arylacetamido side chain. Also, in U.S. Pat. No. 3,579,514, cephalosporins having an .alpha.-(3-guanyl-1-ureido)arylacetamido side chain are described.
A new class of cephalosporin compounds having a substituted carbamido substituent in the .alpha.-position of the 7-arylacetamido side chain has now been discovered. This class of compounds represents the basis of this invention. These compounds, active against both gram-negative and gram-positive pathogens and particularly against Pseudomonas microorganisms, are prepared by acylating the free amino group in the 7-position side chain of a cephalosporin including, for example, cephaloglycin, 7-(D-.alpha.-amino-.alpha.-phenylacetamido)-3-(1-lower alkyl-1H-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid, 7-(D-.alpha.-amino-.alpha.-phenylacetamido)-3-(5-lower alkyl-1,3,4-thiadiazol-2-ylthiomethyl)-3-cephem-4-carboxylic acid, and the like, as well as hydroxy and halogen derivatives thereof with an appropriately structured acylating agent.